In prior art systems for monitoring field devices in a Plant, the statuses of the field devices are used to indicate the health of the devices and this is important for identifying the overall integrity of the Plant. The statuses of the devices are displayed in colours and values in various applications. These applications have different internal algorithms to calculate the status colour. Since different input data and algorithms are used for calculating the values of the status, the calculated values are of different types. Therefore, status values calculated from different applications are displayed separately. This is very inefficient and inconvenient for monitoring the overall Plant status generated from the different applications.
FIG. 1 is an example of a display according of the status calculated by one application. The display is an overall view of the field devices in a plant having a hierarchical relationship. The field devices and their status colour are displayed in an expandable parent folder. If there is more than one field device in a folder, the status colour having the most critical value is displayed for the folder.
There are cases where the calculated status colour is found to be incorrect after an operator has checked the field device physically. This is likely to be caused by an error in the algorithm or data retrieval.
Further, the status of the parent folder is not reflected accurately if the most critical value is from an unimportant field device.
Therefore, there is a need to enable a more accurate status display of the Plant.